"I ran off the longer-run leaflets on a fast, fancy Gestetner mimeograph machine located in Ruth and Hal Draper’s basement..."

"Dunbar Aitkens, publisher of the student science journal Particle, had revived an old Multilith 2066 offset press that had been bought in the early 1960s to print the student journal Root and Branch. On this he and Deward Hastings managed occasionally to get out the FSM Newsletter which gave a four-page analysis of the FSM position on an important topic. Shorter-run leaflets and other mimeographed communications were run off at all hours at Press Central, located in Tom Irwin’s basement on Milvia."

5/2/2012 Lee Felsenstein writes: In the basement of 2417 Milvia (FSM Press Central) we cranked out most of the mimeo'ed leaflets - usually 5,000 per night - that were passed out by squads of volunteers on campus the next day. I had some skill with mimeograph duplication and owned a mo-ped (and had no classes), so in addition to running errands I got to help Bob Dietrich run the poor old A.B. Dick mimeo into its end-of-life condition by the end of the FSM. Presiding over the work there was Thom Irwin, a buddha-like figure with a goatee and glasses, who kept things going and dealt with the press. At the end the mimeo was useless and all that remained was the memory of the constant "snick...snick...snick.." of paper hitting the collection tray.

The hectograph or gelatin duplicator or jellygraph is a printing process which involves transfer of an original, prepared with special inks, to a pan of gelatin or a gelatin pad pulled tight on a metal frame.

mimeograph
http://en.wikipedia.org/wiki/Mimeograph

http://www.thedetroiter.com/nov04/mimeograph.html
THE MIMEOGRAPH REVOLUTION:
by Cary Loren
"Many of the radical small journals in the early 1960s were printed on Gestetner mimeograph machines. This allowed cheap and reasonably readable copies to be made and distributed quickly. The mimeograph was a large, heavy, solid metal machine. Before a copy could be run off, a stencil needed to be made first. Most stencils were usually typewritten on, and then strapped to the machine drum. A hand turned crank (later replaced by an electric motor) would put pressure between sheets of paper and a cylinder as ink was forced through openings cut into the stencil. The entire process went smoothly for professional printers, but for most users (i.e., the do-it-yourself crowd) it was a messy business with torn stencils, ruined ink-stained clothes and smearing ink on the pages. "

3/25/2012: Lee Felsenstein writes:
Ditto (a brand name) masters are not stencils but are opaque paper with a carbon-type impression on the back made by typing or scribing on the front against a carbon-type backing. The material on the back is in fact the ink used to create the copies, dissolved off by an alcohol-soaked wick during the printing process. In doing so, the impression starts out vivid and becomes fainter as more copies are printed. 150 is generally the highest number of copies that can be obtained from a Ditto master. The Rossman-Hollander report was printed by Ditto, as I recall (it was to be distributed to the Regents, press and a few others, apparently - I was not there for it).

"Mimeo masters" are true stencils, made on oil-impregnated porous paper where the oil-bearing fibers are displaced by pressure from a typewriter or stylus so as to allow liquid ink to flow through and be impressed on the paper during the printing process. As you no doubt know by now, they are hard to read but can be read on a light box if they were preserved properly (ink blotted out onto absorbent folders and not allowed to congeal in the open portions of the stencil. They would last for up to 10,000 impressions before beginning to stretch and tear, and could be repaired through skilled use of collodion (correction fluid - ether-based dissolved plastic).

The duplicator used two-ply "spirit masters". The first sheet could be typed, drawn, or written upon. The second sheet was coated with a layer of wax that had been impregnated with one of a variety of colorants. The pressure of writing or typing on the top sheet transferred colored wax to its back side, producing a mirror image of the desired marks. (This acted like a reverse of carbon paper.) The two sheets were then separated, and the first sheet was fastened onto the drum of the (manual or electrical) machine, with the waxed side out.

There is no ink used in spirit duplication. As the paper moves through the printer, the solvent is spread across each sheet by an absorbent wick. When the solvent-impregnated paper comes into contact with the waxed original, it dissolves just enough of the pigmented wax to print the image onto the sheet as it goes under the printing drum.

The usual wax color was aniline purple, a cheap, durable pigment that provided good contrast, but masters were also manufactured in red, green, blue, black, and the hard-to-find orange, yellow, and brown. All except black reproduced in pastel shades: pink, mint, sky blue, etc. Ditto had the useful ability to print multiple colors in a single pass, which made it popular with cartoonists. Multi-colored designs could be made by swapping out the waxed second sheets; for instance, shading in only the red portion of an illustration while the top sheet was positioned over a red-waxed second sheet. This was possible because the pungent-smelling duplicating fluid (typically a 50/50 mix of isopropanol and methanol) was not ink, but a clear solvent.